Usually "investment" implies that you give money to a company so they can cover up front costs (such as tooling costs, r&d costs etc) that will allow them to profit later. The idea is that a certain amount of money now will allow them to make a profit later by selling whatever product the investment allows them to build.
But that doesn't seem to be the case here. Reading between the lines, it sounds like Purism lacks the funds to fulfill the preorders that have already been paid, and the "investment" will just go into fulfilling existing orders. There is little potential for future profit, and instead it just sounds a bit like a ponzi scheme, where they have to keep finding new people to invest in the company.
The term 'investment' holds different meanings depending on the context. For instance, in macroeconomics, 'investment' refers to the addition of capital stock to an economy, which closely aligns with your description. This can involve the incorporation of equipment, buildings, or infrastructure, and is generally anticipated to promote economic growth. The notion that investment capital is spend on something productive in the long-term applies here, but not so much in other contexts.
In sociology, 'investment' often means the expenditure of time or energy into a cause or relationship. In personal finance, 'investment' pertains specifically to the use of financial instruments or products. Overall, 'investment' can mean many things; there isn't really one thing it usually implies.
In the context of business and finance, 'investment' indicates the allocation or transfer of money/resources. However, this doesn't necessarily lead to the acquisition of any assets other than the money itself. For example, I could invest capital into my own company without immediately allocating that money to specific uses — it could just sit in the corporate bank account. The funds could eventually be used in a variety of ways. While it's both morally and ethically commendable to inform investors about the intended uses of their investments, there's no definitive principle stating that such investments must be allocated to specific items like tooling, R&D, and the like.
I understand why people who think that investment implies that would be disappointed by Librem's actions here. But from a business perspective, investing into fulfilling past orders is fine, it still adds business net worth and investor value. Many large companies like Tesla do it, too.
It is not a Ponzi scheme unless the previous investors are directly paid dividends from new investors. A Ponzi scheme is a very specific term. Many businesses operate in a way in which investment grows the business, and this growth pays dividends to previous investors. That could be seen as a Ponzi-like scheme from some perspectives, but it would be a bit contrived, as this is how many highly-leveraged businesses operate.
But that doesn't seem to be the case here. Reading between the lines, it sounds like Purism lacks the funds to fulfill the preorders that have already been paid, and the "investment" will just go into fulfilling existing orders. There is little potential for future profit, and instead it just sounds a bit like a ponzi scheme, where they have to keep finding new people to invest in the company.